Apparatus for the development of light sensitive material



1937. F. w. VON MEISTER E! m. 2,096,015

APPARATUS FOR THE DEVELOPMENT OF LIGHT SENSITIVE MATERIAL Filed March 9,1935 3 Sheets-Sheet 1 r M M a n A o 5 W m m N .Z 8 N a a d r km m Z r Y/0- I m J p yky B k0 V QM I a O:\ Q fl5N Q v6 mm. o ww ww |||l||| ||||I||I. \w m E m l |||||||||||l||1||1|| I Q R m '3 N M "w r1, l I I I'll: v II I'll. k l 'u l l Ill M Li O W @AL 1% ATTORNEY Z 5 Och 1937- F. w. VONMEISTER ET AL 2,096,015

APPARATUS FOR THE DEVELOPMENT OF LIGHT SENSITIVE MATERIAL Filed March 9,1935 3 Sheets-Sheet 2 WHHII Z32 ven%07-5. fietozw/c/r 14 mm ME/ 5 r52FEEDER/CK 14/ Amp 25w .7M 50 Aifo'r'n ey Oct. 19, 1937,

F. W. VON MEISTER ET AL APPARATUS FOR THE DEVELOPMENT OF LIGHT SENSITIVEMATERIAL 3 Sheets-Sheet 3 Filed March 9, 1955 FIG- 5 FIG 4 INVENTORSATTORNEY mum m mmmw Frederick W 1/072 Mez'szfer and Frederick PM AndrewPatented Oct. 19, 1931 2,096,015

UNITED STATES PATENT OFFICE APPARATUS FOR THE DEVELOPMENT OF LIGHTSENSITIVE MATERIAL Frederick W. von Meister, New York, and Frederick W.Andrew, Glen Head, N. Y., assignors to Ozalid Corporation, New York, N.Y., a corporation of Delaware Application March 9, 1935, Serial No.10,208 .4 Claims. (Cl. 95-94) This invention relates to apparatus fordeveloping light-sensitive material, particularly lightsensitivematerial which is developed by a dry process in which ammonia or otherchemically I active developing gas furnishes the developing medium. Manytypes of apparatus have been suggested for this purpose. For the mostpart, these machines are large, cumbersome, inconvenient, and expensiveto manufacture. It is,

10 therefore, one of the objects of this invention to provide a machine,which is relatively light, inexpensive to manufacture, and eflicient tooperate.

Another of the objects of this invention is to II provide a circulatorysystem for the liquid containing the. chemically active gas, which willautomatically deliver said liquid to the generator or developing tankwhen the machine starts to operate, will deliver said liquid only at arate 20 necessary for the proper development of the light-sensitivematerial, andwill automatically cease delivering said liquid when themachine is out of operation. This system being completely self-containedprevents the escape of any gas from the liquid into the room.

' A further object of this invention is the provision of an automaticheat-control mechanism within the ammonia generating tank, designed tomaintain the temperature above the -dew point,

so since the development of certain types of lightsensitive materials isaccomplished best in a heated and humid atmosphere.

Still another object of this invention is the provision of a novel typeof belt guide system 35 designed to keep the endless belt travellingover two guide rollers in a substantially straight path by recenteringitself through the belt guides.

Other features relating to the means of generating or supplying thedeveloping gas andv pre- 40 venting its escape, and means relating tothe unique manner of delivering the developed subject to the operator,will appear below in the detailed description of our apparatus.

The accompanying drawings represent a pre- 45 ferred embodiment of ourinvention: Fig. 1 is an elevation of the back view of the machine. Fig.

2 is an end view of the machine. Hg. 3 is a section taken along the line3-3 of Fig. 1. Fig. 4 is a schematic diagram of the electric wiring.Fig.

50 5 is a longitudinal section of the developing gas generating tank.Hg. 6 is-a'dlagrammatical representation of the delivery system for theliquid containing the chemically active gases. Fig. '1

is a section in elevation of the liquid drip glass.

65 Fig. 8 is a descriptive plan view of the belt and guides. Fig. 9 is asection taken along the line 99' of Fig. 8.

Similar reference characters denote similar elements throughout thevarious views.

Character i represents a developing tank constructed of any suitablemetal, having a perforated curved top, the perforations 2 of which arerelatively small in diameter. The developing tank has open ends. Theends of the tank I are closed by clamping the tank between the two endplates 3 of the machine, using heat insulating gaskets, for instancerubber gaskets 4 over the ends of the tank I, to insure a tight gasproofjoint between the tank and the end plates of the machine and to provideinsulation to re duce heat transfer. An endless rubber belt or blanket 5travelling over rollers 6 and 6' is pulled across the curved perforatedtop of tank i, being frictionally driven by the actuating roller 6'which rotates about its shaft 8' carried by bearings l4 and I4, whichlatter are mounted on the end plates 3 of the machine. Belt guides 5a,rigidly fastened to the end plates 3, prevent the belt from wandering.These belt guides are slotted and so arranged as to have guide piecesbetween the top and bottom guide plates which are at an angle to thetravelling edges of the belt, so that when thebelt travels or wandersfrom right to left, or vice versa, the edge of the belt is led on to theidling roller (6) at an angle thereby offsetting the belts tendency tocreep or wander. Actuating roller 6' may be driven by any suitablemeans. The driving means shown in Fig. 1 comprises a motor l3 mounted onshaft [2 and operating through a flexible coupling II and reduction gearIII. The driving pulley 9, also mounted on shaft l2, transmits the powerto the driven pulley I mounted on roller-shaft 8' through the chain l5.Only one of the rollers, the back one 6', drives the belt 5. The forwardroller 6 is floating. The belt 5 is, therefore, pulled snugly over thecurved top of the developing tank.

A small closed tank l6, having compartments l1 and i3, is mounted on thebase 20 of the machine. Compartment ll constitutes an ammonia supplytank which may be filled from the outside through funnel 2| and deliverypipe 22. A gauge-glass 23, provided with an ammonia hydrometer 24, isattached to the supply tank I I through the end plates 3 of the machine.Connecting pipes 25 and 26 allow a free flow of liquid from the tank tothe gauge. The operator is thereby enabled to check the level andconcentration of the aqueous ammonia in the supply tank at all times.

A unique pumping system, shown diagrammatically in Fig. 6, delivers theaqueous ammonia from the supply tank H to developing tank I. Pump meansof a variable volume type as, for instance, a rubber bulb 21, having oneway valves 28 and 28' on either end thereof, is seated on a stationaryform 46 mounted inside the ammonia supply tank. The bulb 21 is connectedto a drip glass reservoir 29 through a delivery tube. An over-flow pipe3| carries excess aqueous ammonia back to the supply tank. A valvemember 32, which engages a small opening 33 at the bottom of the dripglass reservoir, can be adjusted by adjusting pin 35'to permit theproper flow of the solution through to. the developing tank I. A duct 34carries the dripped ammonia from the drip glass to thedeveloping tank. Atube 54, connecting the ammonia duct 34 with the vapor space of thereservoir 29, serves to equalize the pressure on the-system. .Drain line36 carries the spent ammonia solution to the waste tank or compartmentHi, from which it may be drained from time to time by valve-connection31. A small aperture 38 in the dividing wall IQ of tank l6 normallyserves as a pressure equalizing means between the waste tank l8 and thesupply tank II, but in addition provides an over-flow outlet for thewaste tank l8, if the waste tank should not be drained properly.

The rubber bulb 21 is compressed by a plate 39 integrally connected to aplunger or pump rod 40 and acting against the pressure of the stationaryform 46. The pump rod 40 is pin-connected to a plunger arm or lever 4 I,which is pivotally connected to lever arm 42 which,- in turn, is rigidlyfastened to the end plate 3. The plunger arm 4| is actuated by tappet 43guided by tappet-guide 44 and operated by a cam 45 rigidly fastened tothe drive-roller B.

The ammonia gas is vaporized from the aqueous ammonia supplied to thedeveloping tank or ammonia generating tank I by means of one or moreelectric heater units. Approximately 600 watts are required to heat upthe developing tank, vaporize the ammonia from the liquid fedthereto,-and maintain the vapor at a temperature above its dew point. Inour preferred embodiment of the invention we provide two heater units 41and 48 of 300 watts each inside the developing tank I in the vapor spacethereof, and two heater units 49 and 49a also of 300 watts each in thecompartment 50 fastened adjacent the bottom of the tank. One of theinside heaters 48 and one of the outside heaters 49 are connected to athermostatic switch 5|, which automatically breaks contact when thedesired temperature is reached thereby cutting out one inside heater andone outside heater. The heaters which are not out out serve to maintainoperating temperatures, that is, they supply the heat necessary tocontinuously vaporize ammonia from the aqueous ammonia and to maintainthe ammonia and water vapor above its dew point. When the temperaturedrops below the desired point, the thermostatically controlled heatersare automatically thrown in again. A pilot light 52 or some similarindicating device is connected across the line of the thermostaticallycontrolled heaters to indicate when operating temperature has beenreached.

We provide two bellcranks 60 pivotally connected at the free endsthereof to the end plates 3 of the machine through any suitabletightening means, such as a spring, rods, and turn buckle. The fixedends of the bell cranks 60 are attached through suitable bearings ateither end of the shaft 8 of front roller 6. This front roller 8 floatsin the bell crank bearings in order to provide means for tightening therubber belt 5 so that a substantially gas-tight connection may bemaintained between the endless belt 5 and the curved perforated top ofthe developing tank thereby sealing the latter against the escape offumes from the developing medium.

A bank of formed wires 53 of any suitable metal is provided to receivethe developed subject and guide it to a suitable aperture 55 inthe frontof the machine. We select wires for this purpose, because we have foundthat the amount of static and friction is relatively small when usingwires, whereas it is of objectionable proportions when sheet metal orother similar media are used. These wires 53 are attached to the frontof the base plate 20, slope back gradually curving under the developingtank I to allow proper clearance, and terminate in a position in theback of the machine adjacent the underside of the back-roller 6' and theleaving side of the perforated curved top of tank l.

An exhaust fan 56 of any suitable type is provided to maintain a partialvacuum inside the housing of the machine, to prevent the escape of anyleaking gases and also to remove occluded vapors from the developedsubject. The machine itself is covered with sheet metal removably boltedto the end plates 3, forming a housing for the working parts andpreventing gases from escaping into the room. Suitable ducts may beprovided for carrying fumes from the blower of the machine to theoutside of the building.

The many advantages of our machine over similar devices for thedevelopment of lightsensitive material may be readily ascertained fromthe foregoing detailed description. Thus it can be seen that our uniqueammonia pumping system, operating automatically from the drivingmechanism, insures a steady even flow of aqueous ammonia to thedeveloping tank and only while the machine is in operation. When themachine is not in use, the pump does not function and ammonia is notdelivered to the developing tank in excess of that held in the dripreservoir. It will be observed that we provide a direct connectionbetween the developing tank and the waste tank, also an opening betweenthe waste tank and the supply tank, and an open passage from thedelivery line to the drip reservoir or upper chamber of the drip device,all for the purpose of equalizing the pressure in all parts of ourclosed ammonia system in order that there may not be any water lock toprevent the drip device from functioning properly. Former types ofdeveloping machines invariably operate with a gravity ammonia feed,externally controlled. Here, the flow of developing fluid depends uponthe static fluid pressure and is, therefore, generally irregular.Whether or not delivery of developing fluid ceases when the machine isout of operation depends upon the alertness of the operator.

It is thought that our invention and its numerous attendant advantageswill be understood from the foregoing description. It is believed quiteobvious that the various changes can be made in the arrangement of thevarious elements, the form, construction, and type thereof withoutdeparting from the spirit or scope of our invention. The particulardetailed description outlined above represents a preferred embodimentfor the purpose of illustrating the invention. Modifications andmechanical departures which do not impair the operating efliciency ofthe machine and which fall within the scope of our invention will,therefore, readily suggest themselves.

Having now particularly described our invention, what we claim is:

1. In an apparatus for developing light-sensitive material, an ammoniagenerating system which comprises a developing tank, an aqueous ammoniasupply tank, means for pumping the aqueous ammonia to a drip reservoirabove the level of the developing tank, means associated with thereservoir for dripping the ammonia into the developing tank, means forcontinuously removing spent ammonia solution from the developing tank,and means associated with the driving mechanism of the machine toautomatically actuate the pumping means, the said automaticallyactuating means being so associated with the driving mechanism as toinsure that delivery of ammonia to the developing tank ceases when thesaid driving mechanism is stopped.

2. In an apparatus for developing light-sensitive material, an ammoniagenerating system which comprises a developing tank, an aqueous ammoniasupply tank, an aqueous ammonia pump comprising a variable volumepumpmeans adapted to receive liquid through a one way valve in one endthereof and to deliver liquid through a one way valve in the oppositeend, a plunger having a plate on one end thereof adapted to actuate thevariable volume pump means and having its other end-pin-connected to apump arm, and tappet means actuated by a cam rigidly affixed to adrive-roller shaft and adapted to actuate the pump arm, saiddrive-roller shaft being the driving means for the feed mechanism forthe developing apparatus, a drip reservoir above the level of thedeveloping tank, means associated with the reservoir for dripping theaqueous ammonia into the developing tank, and means for continuouslyremoving spent ammonia solution from the developing tank.

3. In an apparatus for developing light-sensitive material, an ammoniagenerating system which comprises a developing tank, an aqueous ammoniasupply tank, an aqueous ammonia pump, an ammonia drip device comprisinga reservoir having an inlet opening and an over-flow opening, a bottomwith sloping sides and a small aperture at the apex thereof, a meteringpin adapted to engage the said aperture, a delivery tube leading to thedeveloping tank, and pressure equalizing means between the reservoir anddelivery chamber, and means for continuously removing spent ammoniasolution irom the developing tank.

4. In an apparatus for developing light-sensitive material, an ammoniagenerating system which comprises a developing tank, an aqueous ammoniasupply tank, an aqueous ammonia pump, a drip device consisting of areservoir having an adjustable metering pin, an over-flow line to removeexcess liquid from the reservoir, a feed line connected to saidreservoir from the aqueous ammonia pump, an outlet line leading to thedeveloping tank and connected to the said reservoir through a feedchamber adapted to receive the drops of aqueous ammonia, a by-pass linebetween the reservoir and the drip feed chamber to equalize pressuresthroughout the system, and means for continuously removing spent ammoniasolution from the developing tank.

FREDERICK W. von MEISTER. FREDERICK W. ANDREW.

